From: Denis Efremov <efremov@linux.com>
To: Julia Lawall <julia.lawall@lip6.fr>
Cc: Michal Marek <michal.lkml@markovi.net>,
Nicolas Palix <nicolas.palix@imag.fr>,
linux-kernel@vger.kernel.org, Joe Perches <joe@perches.com>,
cocci@systeme.lip6.fr
Subject: Re: [Cocci] [PATCH] scripts: coccinelle: check for !(un)?likely usage
Date: Wed, 28 Aug 2019 15:41:43 +0300 [thread overview]
Message-ID: <496b3d09-47a2-3836-2899-d964267993d3@linux.com> (raw)
In-Reply-To: <4E9DDF9E-C883-44F0-A3F4-CD49284DB60D@lip6.fr>
>
> As a human I am confused. Is !likely(x) equivalent to x or !x?
>
> Julia
>
As far as I could understand it:
# define likely(x) __builtin_expect(!!(x), 1)
!likely(x)
!__builtin_expect(!!(x), 1)
!((!!(x)) == 1)
(!!(x)) != 1, since !! could result in 0 or 1
(!!(x)) == 0
!(!!(x))
!!!(x)
!(x)
Thanks,
Denis
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WARNING: multiple messages have this Message-ID (diff)
From: Denis Efremov <efremov@linux.com>
To: Julia Lawall <julia.lawall@lip6.fr>
Cc: Joe Perches <joe@perches.com>,
cocci@systeme.lip6.fr, linux-kernel@vger.kernel.org,
Gilles Muller <Gilles.Muller@lip6.fr>,
Nicolas Palix <nicolas.palix@imag.fr>,
Michal Marek <michal.lkml@markovi.net>
Subject: Re: [PATCH] scripts: coccinelle: check for !(un)?likely usage
Date: Wed, 28 Aug 2019 15:41:43 +0300 [thread overview]
Message-ID: <496b3d09-47a2-3836-2899-d964267993d3@linux.com> (raw)
In-Reply-To: <4E9DDF9E-C883-44F0-A3F4-CD49284DB60D@lip6.fr>
>
> As a human I am confused. Is !likely(x) equivalent to x or !x?
>
> Julia
>
As far as I could understand it:
# define likely(x) __builtin_expect(!!(x), 1)
!likely(x)
!__builtin_expect(!!(x), 1)
!((!!(x)) == 1)
(!!(x)) != 1, since !! could result in 0 or 1
(!!(x)) == 0
!(!!(x))
!!!(x)
!(x)
Thanks,
Denis
next prev parent reply other threads:[~2019-08-28 12:42 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-25 13:05 [Cocci] [PATCH] scripts: coccinelle: check for !(un)?likely usage Denis Efremov
2019-08-25 13:05 ` Denis Efremov
2019-08-25 15:30 ` [Cocci] " Markus Elfring
2019-08-25 15:30 ` Markus Elfring
2019-08-25 21:06 ` [Cocci] " Denis Efremov
2019-08-25 21:06 ` Denis Efremov
2019-08-25 15:30 ` [Cocci] " Markus Elfring
2019-08-25 15:30 ` Markus Elfring
2019-08-25 16:37 ` [Cocci] " Joe Perches
2019-08-25 16:37 ` Joe Perches
2019-08-25 18:59 ` [Cocci] " Denis Efremov
2019-08-25 18:59 ` Denis Efremov
2019-08-25 19:19 ` [Cocci] " Julia Lawall
2019-08-25 19:19 ` Julia Lawall
2019-08-28 11:33 ` [Cocci] " Rasmus Villemoes
2019-08-28 11:33 ` Rasmus Villemoes
2019-08-28 11:59 ` [Cocci] " Joe Perches
2019-08-28 11:59 ` Joe Perches
2019-08-28 12:33 ` [Cocci] " Denis Efremov
2019-08-28 12:33 ` Denis Efremov
2019-08-28 13:05 ` Rasmus Villemoes
2019-08-28 13:14 ` Denis Efremov
2019-08-28 12:33 ` [Cocci] " Julia Lawall
2019-08-28 12:33 ` Julia Lawall
2019-08-28 12:41 ` Denis Efremov [this message]
2019-08-28 12:41 ` Denis Efremov
2019-08-28 13:57 ` [Cocci] " Denis Efremov
2019-08-28 13:57 ` Denis Efremov
2019-08-25 21:19 ` [Cocci] " Denis Efremov
2019-08-25 21:19 ` Denis Efremov
2019-09-01 17:24 ` Pavel Machek
2019-09-01 17:39 ` [Cocci] " Denis Efremov
2019-09-01 17:39 ` Denis Efremov
2019-08-29 17:10 ` [Cocci] [PATCH v2] " Denis Efremov
2019-08-29 17:10 ` Denis Efremov
2019-08-29 17:13 ` [Cocci] " Denis Efremov
2019-08-29 17:13 ` Denis Efremov
2019-08-30 0:42 ` [Cocci] " Julia Lawall
2019-08-30 0:42 ` Julia Lawall
2019-08-30 6:56 ` [Cocci] " Denis Efremov
2019-08-30 6:56 ` Denis Efremov
2019-08-30 8:06 ` [Cocci] " Rasmus Villemoes
2019-08-30 8:06 ` Rasmus Villemoes
2019-08-29 20:07 ` [Cocci] " Markus Elfring
2019-08-29 20:07 ` Markus Elfring
2019-08-30 7:55 ` [Cocci] " Markus Elfring
2019-08-30 7:55 ` Markus Elfring
2019-08-30 7:55 ` Markus Elfring
2019-09-06 20:19 ` [Cocci] " Julia Lawall
2019-09-06 20:19 ` Julia Lawall
2019-09-06 20:55 ` [Cocci] " Denis Efremov
2019-09-06 20:55 ` Denis Efremov
2019-09-07 8:05 ` [Cocci] [v2] " Markus Elfring
2019-09-07 8:05 ` Markus Elfring
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